Soap wrapper



Patented July 2, 1940 soar w Lawrence W. dtrattner, Meccville, N. EL, assignor to West Virginia Pulp and Paper Company, New York, N. Y., a corporation of Dela! No Drawing. 'application December 18,1988,

Serial No. 2&6122

My present invention relates to an improved soap wrapper of paper. Dificulty has heretofore been experienced with soap wrappers of paper, made from pulps not specially treated for 5 the purpose, in that the wrapper becomes discolored aiter contact with the soap over a short period of time, such discoloration being yellow to brownish. This discoloration of the paper is due to the action of the alkali in the soap.

Papers which show this effect to only a slight extent can be made from specially treated pulps, which treatment generally involves a mild caustic digestion, either during or after bleaching. Such treatment adds to the expense of the pulp and may actually be impracticable for mills in which pulp for soap-wrapper paper constitutes only a small percentage of the totai product.

I have now discovered that the presence of calcium sulfite in a paper made from normally bleached pulp, not treated as mentioned above, substantially prevents this discoloration. Preierably calcium sulfite is used in lieu of clay or other filling material, although it is not necessary that the filler be entirely of calcium sulfite; and in practice I have successfully used as little as 6.0% of calcium sulflte based on the weight of the paper. a

The following is a preferred example of a furnish for a paper constituting my improved soap wrapper:

Pounds Normally bleached and untreated sulfite pulp 850 Calcium sulfite 150 Size as represented by the following quantities:

Dry rosin 30 Alum 20 suliite used is less than the total filler, it may be admixed with other fillers commonly used, c. a" clay, chalk, calcium sulfate or' mixtures thereof.

My best explanation for the action of the 5 calcium sulfite is that it acts as a reducing agent in the manufacture of the sheet and prevents or limits the formation of oxidation products which cause discoloration in the presence of alkali. Furthermore, the calcium sulfite in the finished w sheet reacts chemically with any alkali in the soap to convert it into a less active form. In any event, when my improved sheet is tested with a drop of 1% alkali solution and allowed to dry (the standard alkali test for soap wrappers) the discoloration is a barely perceptible light yellow instead of the customary brown.

An outstanding advantage of my improved wrapper is that a protecting sheet or liner between the wrapper and the soap is no longer necessary for the purpose of preventing the appearance of the wrapper, which usually carries printing and often other ornamental matter, from being spoiled by becoming discolored, even when paper made from untreated pulp is used.

I claim:

1. In combination, a cake of soap and a wrapper of paper therefor in contact with the soap, said wrapper containing a filler comprising calcium sulfite in an amount sumcient to prevent substantial discoloration of the wrapper from alkali contained in the soap.

2. In combination, a cake of soap and a wrapper of paper therefor in contact with the soap, said wrapper containing normally bleached and untreated chemical pulp and a filler comprising calcium sulflte in an amount sufficient to prevent substantial discoloration from alkali contained in the soap.

3. In combination, a cake of soap and a wrapper of paper therefor, said wrapper having one surface in contact with the soap and its outer surface adapted to carry printing or decoration, said wrapper containing a filler compris- 45 lng calcium sulfite in an amount sufflcient to prevent substantial discoloration from alkali contsined in the soap. I

LAWRENCE W. STRA'I'I'NER. so

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